DESCRIPTION: This study is examining the feasibility of flood risk management alternatives to address flooding issues within the Township of Denville. Denville is a municipality located within Morris County, New Jersey which is approximately 25 miles northwest of Newark. The study is focused on the central part of Denville, which is subject to fluvial flooding from the Rockaway River and Den Brook. Township residents and businesses have suffered extensive losses and damage from multiple flooding events in recent decades, including Hurricane Irene in August 2011 and Tropical Strom Ida in September 2021. An integrated feasibility report and environmental assessment will document the analysis and conclusions of the study.
AUTHORIZATION: This study is being conducted under Section 205 of the Continuing Authorities Program (CAP), which does not require individual study authorization.
STATUS: As a part of this study, which is an iterative process, the Project Delivery Team (PDT) has analyzed several different flood risk management alternatives. Throughout the process the PDT has coordinated their work with the New Jersey Department of Environmental Protection (NJDEP), who is the non-Federal sponsor, and the Township of Denville, who is a stakeholder on the project. Alternatives studied to date have included various structural measures such as floodwalls with closure gates, floodwalls in combination with road raisings, and diversion culverts. None of these structural alternatives analyzed were found to be economically justified so they could not move forward.
In addition to the structural alternatives the PDT has also analyzed nonstructural measures such as elevations, wet floodproofing, and dry floodproofing. The nonstructural analysis conducted by the PDT identified multiple groups or clusters of structures within the study area that were economically justified which indicates the benefits outweighed the costs. On November 20th, 2020 the PDT briefed our higher headquarters, USACE North Atlantic Division (NAD), at a Tentatively Selected Plan milestone in which approval was given to advance the nonstructural plan and complete a draft integrated feasibility report and environmental assessment for public release on the fall of 2023.
The draft report was developed following the public comment period. Currently the final report is in the final stages with completion slated for late 2024. Upon completion of the final report, the findings will be coordinated with the NFS as well as the city of Denville, and then formal submission to HQ USACE for final review and approval will occur. Upon approval of the final decision documents, the design and implementation phase will be subject to availability of funding in coordination with non-Federal sponsors and local partners.
CONTACT:
Evan Nelson
Project Manager
P: (917) 790-8350
Email: evan.m.nelson@usace.army.mil
U.S. Army Corps of Engineers, New York District
26 Federal Plaza
New York, NY 10278
CONGRESSIONAL DISTRICTS:
NJ-11